The electronics used in such automotive, aerospace, and military vehicles are subjected to more challenging application environments than those present in the computer and telecommunication sectors. The CAVE3 Center is built around commonality of themes related to electronic systems in the automotive, military, defense, aerospace and space-based applications. The focus of the center research is on innovation in design, reliability, prognostics, and manufacturability of electronics for future emergence of cost-effective, damage tolerant electronic systems.

Center Mission and Rationale

The NSF Industry/University Cooperative Research Center for Advanced Vehicle and Extreme Environment Electronics (CAVE3, also known as CAVE) was established at Auburn University in 1999 to develop and implement new technologies for the packaging and manufacturing of electronics, with emphasis on the harsh environment, reliability, prognostics and cost. Today, the Center is a premier research world-class organization in the area of harsh environment electronics. The center provides an ideal forum in which academia and industry work in partnership on identification of key road blocks relevant to electronics in harsh environments and development of innovative technologies for enabling cost-effective solutions. The Center membership is vertically integrated to include OEMs as well as their supply infrastructure including manufacturers of components, printed wiring boards, and electronics materials. The focus of the center research is on innovation in design, reliability, prognostics, and manufacturability of electronics for future emergence of cost-effective, damage tolerant electronic systems. Electronics in harsh environments typical of automotive, military, defense, aerospace and space-based applications may be subjected to severe high and/or low ambient temperatures; extreme temperature changes; moisture and high humidity; exposure to dirt, contaminants, chemicals, and radiation; and excessive transient loadings, shock/drop, and vibration. EMI/RFI (Electro Magnetic Interference /Radio Frequency Interference) shielding from internal and external noise, and ESD (Electro Static Discharge) are also critical factors. Commercial off-the-shelf technologies may not address the reliability and life-cycle needs of the extreme environment applications. These themes provide the motivation for the Center’s strategic directions related to technology development and research resource allocation.

In this research area, reliable component packaging technologies (BGA, CSP, 3D Packaging, QFN, etc.) are being developed for harsh environments such as automotive under-the-hood and aerospace applications and also for portable electronic products such as cell phones. The major goal is to develop fundamental knowledge on the interactions between component design and material selection on package reliability and thermal performance in harsh thermal cycling and vibration environments. Develop guidelines on the selection and use of components in harsh environments. Develop accelerated Test Data on Electronic Structures including but not limited to - metal backed boards, high Tg laminates subjected to extreme environments. Deliverables include crack propagation and damage models; thermal cycling reliability data; algorithms for prognostication; computational models for reliability and thermal performance; design guidelines and decision support tools; and models for shock, drop, and vibration.

CONNECTORS AND SYSTEM-LEVEL INTERCONNECTS

In this research area, the effects of vibration and environment on the performance of automotive and other harsh environment connectors are being evaluated. The primary goals are to examine connector interconnection options for next generation extreme environment applications and to establish the reliability and failure mechanisms. A basic understanding of the causes of fretting corrosion is being established, and then utilized to develop strategies for the accelerated testing of connectors. In addition, the growth of tin whiskers is being studied on connector pins with lead free plating finishes. The ongoing tin whisker research includes both fundamental studies on the origin of whisker growth and experimental test matrices to examine next generation connector designs. Deliverables from our Connector Reliability research include design guidelines, modeling tools, reliability data, and processing recommendations.

LEADFREE SOLDERS ALLOYS CONSTITUTIVE AND WETTING BEHAVIOR

In this research area, potential lead-free solder alloys and corresponding lead-free surface finishes (board and component) are being identified to replace eutectic 63Sn-37Pb solder in harsh environment applications. The primary goal is to develop a fundamental unde rstanding of alternate solder alloys that will meet the high reliability, and high volume low cost manufacturing needs of the vehicle industry. Deliverables include recommended solder alloys; solderability (wetting) measurements; thermal cycling reliability data, stress-strain and creep results as a function of temperature, constitutive and solder fatigue models; and processing recommendations.

PROGNOSTICS HEALTH MANAGEMENT SYSTEMS

Leading indicators-of-failure are being developed for interrogation of material state significa ntly prior to appearance of any macro-indicators. The research focus is on determination of residual life of electronic systems via on-board sensing, damage-detection algorithms and data processing. Environments being studied include single, sequential, simultaneous thermo-mechanical, hygro-mechanical and dynamic loads. PHM is a key enabling technology with applications to avionic, automotive, and bio-implantable electronic systems.

Special Activities

The Center has developed an online software interface for the reliability and prognostics of harsh environment electronics. The tool-sets have been created in the two general areas including finite element tool add-ons for high-end simulation of electronic assemblies on commercial FE platforms, and closed-form modeling tool-set for the turn-key assessment of part reliability, risk-informed technology assessment, and part life-cycle management. The software tools are intended to operationalize the results from center research and put it in the hand of the industry practitioners and product development teams.

Facilities and Laboratory

Auburn University has a demonstrated research focus on electronics reliability. Extreme Environment Experimental research capabilities include several laboratories including a surface-mount assembly line. It is believed that these facilities are among the best available at any university in the nation in the areas of electronic assembly, packaging, and reliability. A description of these and other facilities is given below.

MODELING AND SIMULATIONS TOOLS: The laboratory has a full suite of computer-aided design, and high-end simulation tools. Computer-aided design tools include Pro-Engineer and Solid Edge. Simulation tools include, ANSYS, LS-DYNA, ABAQUS, ABAQUS/Explicit, NASTRAN, and MATLAB. The laboratory is well equipped with dual-processor Pentium-class workstations, and Unix multi-processor compute server.